<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <script>
    Promise.all([
      new Promise((resolve, reject) => {
        setTimeout(() => {
          resolve('aaa')
        }, 1000)
      }),
      new Promise((resolve,reject)=>{
        setTimeout(() => {
          resolve('bbb')
        }, 2000)
      })
    ]).then(results => {
      console.log(results[0]+results[1]);
    })

  </script>
</body>

</html>